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API changes between versions

This page lists the main changes in the OpenFAST API (input files) between different versions.

The changes are tabulated according to the module input file, line number, and flag name. The line number corresponds to the resulting line number after all changes are implemented. Thus, be sure to implement each in order so that subsequent line numbers are correct.

OpenFAST v4.0.0 to OpenFAST v4.0.1

No input file changes are required. MoorDyn can contain an option section for External Loads (see the MoorDyn documentation for details here).

Modified in OpenFAST v4.0.1
Module Line Flag Name Example Value
MoorDyn *   New optional sections for EXTERNAL LOADS (freeform file). See MoorDyn documentation for details (here)

*Exact line number depends on number and size of preceeding sections.

OpenFAST v3.5.5 to OpenFAST 4.0.0

The HydroDyn module was split into HydroDyn and SeaState. This results in a completely new input file for SeaState, and complete revision of the HydroDyn input file. See examples in the regression tests for the new formats.

New modules AeroDisk (see :numref:`ADsk`), Simplified-ElastoDyn (see :numref:`SED`), and SeaState (see :numref:`SeaSt`) were added. See documentation on those modules for exmple input files.

Modified in OpenFAST v4.0.0
Module Line Flag Name Example Value
OpenFAST 13 CompElast 3 CompElast - Compute structural dynamics (switch) {1=ElastoDyn; 2=ElastoDyn + BeamDyn for blades; 3=Simplified ElastoDyn}
OpenFAST 15 CompAero** 2 CompAero - Compute aerodynamic loads (switch) {0=None; 1=AeroDisk; 2=AeroDyn; 3=ExtLoads}
OpenFAST 17 CompSeaSt 0 CompSeaSt - Compute sea state information (switch) {0=None; 1=SeaState}
OpenFAST 41 SeaStFile "unused" SeaStFile - Name of file containing sea state input parameters (quoted string)
AeroDyn all   Complete restructuring of input file (see notes below)
AeroDyn Aeroacoustics 11* TI 0.1 TI - Rotor-incident wind turbulence intensity (-) [Only used if TiCalcMeth == 1]
AeroDyn Aeroacoustics 12* avgV 8 avgV - Average wind speed used to compute the section-incident turbulence intensity (m/s) [Only used if TiCalcMeth == 1]
HydroDyn all   Complete restructuring of input file
SeaState all   New module (split from HydroDyn, so contains some inputs previously found in HydroDyn)
AeroDisk all   New module
Simplified-ElastoDyn all   New module
ElastoDyn 84 PtfmXYIner 0 PtfmXYIner - Platform xy moment of inertia about the platform CM (=-int(xydm)) (kg m^2)
ElastoDyn 84 PtfmYZIner 0 PtfmYZIner - Platform yz moment of inertia about the platform CM (=-int(yzdm)) (kg m^2)
ElastoDyn 84 PtfmXZIner 0 PtfmXZIner - Platform xz moment of inertia about the platform CM (=-int(xzdm)) (kg m^2)
ElastoDyn 101   ---------------------- YAW-FRICTION --------------------------------------------
ElastoDyn 102 YawFrctMod 0 YawFrctMod - Yaw-friction model {0: none, 1: friction independent of yaw-bearing force and bending moment, 2: friction with Coulomb terms depending on yaw-bearing force and bending moment...
ElastoDyn 103 M_CSmax 300 M_CSmax - Maximum static Coulomb friction torque (N-m) [M_CSmax when YawFrctMod=1; abs(Fz)*M_CSmax when YawFrctMod=2 and Fz<0]
ElastoDyn 104 M_FCSmax 0 M_FCSmax - Maximum static Coulomb friction torque proportional to yaw bearing shear force (N-m) [sqrt(Fx^2+Fy^2)*M_FCSmax; only used when YawFrctMod=2]
ElastoDyn 105 M_MCSmax 0 M_MCSmax - Maximum static Coulomb friction torque proportional to yaw bearing bending moment (N-m) [sqrt(Mx^2+My^2)*M_MCSmax; only used when YawFrctMod=2]
ElastoDyn 106 M_CD 40 M_CD - Dynamic Coulomb friction moment (N-m) [M_CD when YawFrctMod=1; abs(Fz)*M_CD when YawFrctMod=2 and Fz<0]
ElastoDyn 107 M_FCD 0 M_FCD - Dynamic Coulomb friction moment proportional to yaw bearing shear force (N-m) [sqrt(Fx^2+Fy^2)*M_FCD; only used when YawFrctMod=2]
ElastoDyn 108 M_MCD 0 M_MCD - Dynamic Coulomb friction moment proportional to yaw bearing bending moment (N-m) [sqrt(Mx^2+My^2)*M_MCD; only used when YawFrctMod=2]
ElastoDyn 109 sig_v 0 sig_v - Linear viscous friction coefficient (N-m/(rad/s))
ElastoDyn 110 sig_v2 0 sig_v2 - Quadratic viscous friction coefficient (N-m/(rad/s)^2)
ElastoDyn 111 OmgCut 0 OmgCut - Yaw angular velocity cutoff below which viscous friction is linearized (rad/s)
ElastoDyn blade file 15   Removal of the PitchAxis input column
InflowWind driver 27   ---- Output VTK slices ------------------------------------------------------
InflowWind driver 28 NOutWindXY 0 NOutWindXY -- Number of XY planes for output <RootName>.XY<loc>.t<n>.vtk (-) [0 to 9]
InflowWind driver 29 OutWindZ 90 OutWindZ -- Z coordinates of XY planes for output (m) [1 to NOutWindXY] [unused for NOutWindXY=0]
MoorDyn --   New optional sections (freeform file). See MoorDyn documentation for details (here)
SubDyn 8 --removed-- removed: GuyanLoadCorrection
SubDyn 12 --removed-- removed: CBMod
SubDyn 56*   ----------------------- SPRING ELEMENT PROPERTIES -------------------------------------
SubDyn 57* NSpringPropSets 0
  • Number of spring properties
SubDyn 58*   PropSetID k11 k12 k13 k14 k15 k16 k22 k23 k24 k25 k26 k33 k34 k35 k36 k44 k45 k46 k55 k56 k66
SubDyn 59*   (-) (N/m) (N/m) (N/m) (N/rad) (N/rad) (N/rad) (N/m) (N/m) (N/rad) (N/rad) (N/rad) (N/m) (N/rad) (N/rad) (N/rad) (Nm/rad) (Nm/rad) (Nm/rad) (Nm/rad) (Nm/rad) (Nm/rad)
FAST.Farm 16 WrMooringVis true WrMooringVis - Write shared mooring visualization, at DT_Mooring timestep (-) [only used for Mod_SharedMooring=3]
FAST.Farm 48* RotorDiamRef 125 RotorDiamRef - Reference turbine rotor diameter for wake calculations (m) [>0.0]
FAST.Farm 53* k_vAmb DEFAULT k_vAmb - Calibrated parameters for the influence of the ambient turbulence in the eddy viscosity (set of 5 parameters: k, FMin, DMin, DMax, Exp) (-) [>=0.0, >=0.0 and <=1.0, >=0.0, >DMin, >0.0] or DEFAULT [DEFAULT=0.05, 1.0, 0.0, 1.0, 0.01]
FAST.Farm 54* kvShr DEFAULT k_vShr - Calibrated parameters for the influence of the shear layer in the eddy viscosity (set of 5 parameters: k, FMin, DMin, DMax, Exp) (-) [>=0.0, >=0.0 and <=1.0, >=0.0, >DMin, >0.0] or DEFAULT [DEFAULT=0.016, 0.2, 3.0, 25.0, 0.1]
FAST.Farm 55-62* --removed--  
FAST.Farm 69*   --- WAKE-ADDED TURBULENCE ---
FAST.Farm 70* WAT 2 WAT - Switch between wake-added turbulence box options {0: no wake added turbulence, 1: predefined turbulence box, 2: user defined turbulence box} (switch)
FAST.Farm 71* WAT_BoxFile "../WAT_MannBoxDB/FFDB_D100_512x512x64.u" WAT_BoxFile - Filepath to the file containing the u-component of the turbulence box (either predefined or user-defined) (quoted string)
FAST.Farm 72* WAT_NxNyNz 512, 512, 64 WAT_NxNyNz - Number of points in the x, y, and z directions of the WAT_BoxFile [used only if WAT=2, derived value if WAT=1] (-)
FAST.Farm 73* WAT_DxDyDz 5.0, 5.0, 5.0 WAT_DxDyDz - Distance (in meters) between points in the x, y, and z directions of the WAT_BoxFile [used only if WAT=2, derived value if WAT=1] (m)
FAST.Farm 74* WAT_ScaleBox default WAT_ScaleBox - Flag to scale the input turbulence box to zero mean and unit standard deviation at every node [DEFAULT=False] (flag)
FAST.Farm 75* WAT_k_Def default WAT_k_Def - Calibrated parameters for the influence of the maximum wake deficit on wake-added turbulence (set of 5 parameters: k_Def, FMin, DMin, DMax, Exp) (-) [>=0.0, >=0.0 and <=1.0, >=0.0, >DMin, >0.0] or DEFAULT [DEFAULT=[0.6, 0.0, 0.0, 2.0, 1.0 ]]
FAST.Farm 76* WAT_k_Grad default WAT_k_Grad - Calibrated parameters for the influence of the radial velocity gradient of the wake deficit on wake-added turbulence (set of 5 parameters: k_Grad, FMin, DMin, DMax, Exp) (-) [>=0.0, >=0.0 and <=1.0, >=0.0, >DMin, >0.0] or DEFAULT [DEFAULT=[3.0, 0.0, 0.0, 12.0, 0.65]

*Exact line number depends on number of entries in various preceeding tables.

** The AeroDyn 14 module has been removed and replaced with AeroDisk. AeroDyn15 renamed to AeroDyn

New Modules

  • AeroDisk -- reduced order actuator disk model (see :numref:`ADsk`)
  • Simplified ElastoDyn -- a reduced order structural model with only yaw and rotor speed degrees of freedom (see :numref:`SED`)
  • SeaState -- wave dynamics calculations (previously part of HydroDyn)

AeroDyn changes starting from v4.x

The table below shows how to convert from the Old AeroDyn inputs to the new AeroDyn inputs. Additional ressources:

Old inputs Corresponding new inputs
WakeMod=0 Wake_Mod=0
WakeMod=1 ("BEM") Wake_Mod=1 and DBEMT_Mod=0 and BEM_Mod=1
WakeMod=2 ("DBEMT") Wake_Mod=1 and DBEMT_Mod={1,2,3}
WakeMod=3 ("OLAF") Wake_Mod=3
AFAeroMod=1 UA_Mod=0 and AoA34=False
AFAeroMod=2 UA_Mod>0 and AoA34=True and UA_Mod=UAMod
FrozenWake=True DBEMT_Mod=-1
FrozenWake=False DBEMT_Mod=0 (quasi-steady) or DBEMT_Mod>0 (dynamic)
SkewMod=2 (Glauert) Skew_Mod=1 and SkewRedistr_Mod=1
SkewMod=0 (Orthogonal) Skew_Mod=-1
SkewModFactor SkewRedistrFactor
UAMod={2-7} UA_Mod={2-7} and AoA34=True

OpenFAST v3.5.4 to OpenFAST v3.5.5

No input file changes were made.

OpenFAST v3.5.3 to OpenFAST v3.5.4

No input file changes were made.

OpenFAST v3.5.2 to OpenFAST v3.5.3

No input file changes were made.

OpenFAST v3.5.1 to OpenFAST v3.5.2

No input file changes were made.

OpenFAST v3.5.0 to OpenFAST v3.5.1

No input file changes were made. Some input files now include additional output channels: AeroDyn nodal outputs for another coordinate system, new MoorDyn output names (Connect changed to Point).

OpenFAST v3.4.0 to OpenFAST v3.5.0

Updated the CMake build system. Now requires CMake v3.12 or higher.

Modified in OpenFAST 3.5.0
Module Line Flag Name Example Value
ServoDyn-StructCtrl 6 StC_DOF_MODE 2 StC_DOF_MODE - DOF mode (switch) {0: No StC or TLCD DOF; 1: StC_X_DOF, StC_Y_DOF, and/or StC_Z_DOF (three independent StC DOFs); 2: StC_XY_DOF (Omni-Directional StC); 3: TLCD; 4: Prescribed force/moment time series; 5: Force determined by external DLL}
InflowWind 8 VelInterpCubic true VelInterpCubic - Use cubic interpolation for velocity in time (false=linear, true=cubic) [Used with WindType=2,3,4,5,7]
InflowWind 51   ================== LIDAR Parameters ===========================================================================
InflowWind 52 SensorType 0 SensorType - Switch for lidar configuration (0 = None, 1 = Single Point Beam(s), 2 = Continuous, 3 = Pulsed)
InflowWind 53 NumPulseGate 0 NumPulseGate - Number of lidar measurement gates (used when SensorType = 3)
InflowWind 54 PulseSpacing 30 PulseSpacing - Distance between range gates (m) (used when SensorType = 3)
InflowWind 55 NumBeam 0 NumBeam - Number of lidar measurement beams (0-5)(used when SensorType = 1)
InflowWind 56 FocalDistanceX -200 FocalDistanceX - Focal distance co-ordinates of the lidar beam in the x direction (relative to hub height) (only first coordinate used for SensorType 2 and 3) (m)
InflowWind 57 FocalDistanceY 0 FocalDistanceY - Focal distance co-ordinates of the lidar beam in the y direction (relative to hub height) (only first coordinate used for SensorType 2 and 3) (m)
InflowWind 58 FocalDistanceZ 0 FocalDistanceZ - Focal distance co-ordinates of the lidar beam in the z direction (relative to hub height) (only first coordinate used for SensorType 2 and 3) (m)
InflowWind 59 RotorApexOffsetPos 0.0 0.0 0.0 RotorApexOffsetPos - Offset of the lidar from hub height (m)
InflowWind 60 URefLid 17 URefLid - Reference average wind speed for the lidar[m/s]
InflowWind 61 MeasurementInterval 0.25 MeasurementInterval - Time between each measurement [s]
InflowWind 62 LidRadialVel False LidRadialVel - TRUE => return radial component, FALSE => return 'x' direction estimate
InflowWind 63 ConsiderHubMotion 1 ConsiderHubMotion - Flag whether to consider the hub motion's impact on Lidar measurements

OpenFAST v3.4.0 to OpenFAST v3.4.1

Restored the AeroDyn channel names with Aero in the name. These had be changed to Fld in v3.4.0 which caused headaches for users. The Fld names are now aliases to the Aero names.

OpenFAST v3.4.0 to OpenFAST dev

AeroDyn14 has been removed!

Changed in OpenFAST dev
Module Line Flag Name Example Value
OpenFAST 15 CompAero 2 CompAero - Compute aerodynamic loads (switch) {0=None; 2=AeroDyn v15}

OpenFAST v3.3.0 to OpenFAST v3.4.0

Added in OpenFAST 3.4.0
Module Line Flag Name Example Value
FAST.Farm 42* ModWake 1 Mod_Wake - Switch between wake formulations {1:Polar, 2:Curl, 3:Cartesian} (-) (switch)
FAST.Farm 67 CurlSection --- CURLED-WAKE PARAMETERS [only used if Mod_Wake=2 or 3] ---
FAST.Farm 68 Swirl DEFAULT Swirl - Switch to include swirl velocities in wake (-) (switch) [DEFAULT=True]
FAST.Farm 69 k_VortexDecay DEFAULT k_VortexDecay - Vortex decay constant for curl (-) [DEFAULT=0.01] [only used if Mod_Wake=2]
FAST.Farm 70 NumVortices DEFAULT NumVortices - The number of vortices in the curled wake model (-) [DEFAULT=100] [only used if Mod_Wake=2]
FAST.Farm 71 sigma_D DEFAULT sigma_D - The width of the vortices in the curled wake model non-dimensionalized by rotor diameter (-) [DEFAULT=0.2] [only used if Mod_Wake=2]
FAST.Farm 72 FilterInit DEFAULT FilterInit - Switch to filter the initial wake plane deficit and select the number of grid points for the filter {0: no filter, 1: filter of size 1} or DEFAULT [DEFAULT=1] (switch)
FAST.Farm 73 k_vCurl DEFAULT k_vCurl - Calibrated parameter for scaling the eddy viscosity in the curled-wake model (-) [>=0] or DEFAULT [DEFAULT=2.0 ]
FAST.Farm 74 Mod_Projection DEFAULT Mod_Projection - Switch to select how the wake plane velocity is projected in AWAE {1: keep all components, 2: project against plane normal} or DEFAULT [DEFAULT=1: if Mod_Wake is 1 or 3, or DEFAULT=2: if Mod_Wake is 2] (switch)
FAST.Farm 91 OutAllPlanes DEFAULT OutAllPlanes - Output all wake planes at all time steps. [DEFAULT=False]
AeroDyn 15 13 Buoyancy True Buoyancy - Include buoyancy effects? (flag)
AeroDyn 15 65 HubPropsSection ====== Hub Properties ============================================================================== [used only when Buoyancy=True]
AeroDyn 15 66 VolHub 7.0 VolHub - Hub volume (m^3)
AeroDyn 15 67 HubCenBx 0.5 HubCenBx - Hub center of buoyancy x direction offset (m)
AeroDyn 15 68 NacPropsSection ====== Nacelle Properties ========================================================================== [used only when Buoyancy=True]
AeroDyn 15 69 VolNac 32.0 VolNac - Nacelle volume (m^3)
AeroDyn 15 70 NacCenB 0.4,0,0 NacCenB - Position of nacelle center of buoyancy from yaw bearing in nacelle coordinates (m)
AeroDyn 15 71 TFinPropsSection ====== Tail fin Aerodynamics ========================================================================
AeroDyn 15 72 TFinAero True TFinAero - Calculate tail fin aerodynamics model (flag)
AeroDyn 15 73 TFinFile$ "AD_Fin.dat" TFinFile - Input file for tail fin aerodynamics [used only when TFinAero=True]
AeroDyn 15   TwrCb 1.0 [additional column in Tower Influence and Aerodynamics table]
AeroDyn blade   BlCb 0.187 [additional column in Blade Properties table]
AeroDyn blade   BlCenBn 0.3 [additional column in Blade Properties table]
AeroDyn blade   BlCenBt 0.1 [additional column in Blade Properties table]
OLAF 18 nNWPanelFree 180 nNWPanelFree - Number of free near-wake panels (-) {default: nNWPanels}
OLAF 19 nFWPanels 900 nFWPanels - Number of far-wake panels (-) {default: 0}
OLAF 20 nFWPanelsFree 0 nFWPanelsFree - Number of free far-wake panels (-) {default: nFWPanels}

*Exact line number depends on number of entries in various preceeding tables.

$ The content of the tail fin input file is described in :numref:`TF_tf_input-file`.

New Default Values: The following default value were changed

  • OLAF VelocityMethod is now 2 (particle tree), previous value 1 (n^2 BiotSavart law on segments).
  • OLAF WakeRegMethod is now 3 (increasing with wake age), previous value was 1 (constant).
  • OLAF nVTKBlades is now 0 (no wake panels output), previous value was 1 (wake panels output for blade 1)
Removed in OpenFAST v3.4.0
Module Line Flag Name Example Value
OLAF 18 WakeLength 900 WakeLength Total wake distance [integer] (number of time steps)
OLAF 19 FreeWakeLength 0 FreeWakeLength Wake length that is free [integer] (number of time steps) {default: WakeLength}

OpenFAST v3.2.0 to OpenFAST v3.3.0

Added in OpenFAST 3.3.0
Module Line Flag Name Example Value
FAST.Farm 9 ModWaveField 2 Mod_WaveField - Wave field handling (-) (switch) {1: use individual HydroDyn inputs without adjustment, 2: adjust wave phases based on turbine offsets from farm origin}
FAST.Farm 10 Mod_SharedMooring 0 Mod_SharedMooring - Shared mooring system model (switch) {0: None, 3=MoorDyn}}
FAST.Farm 13 na ------ SHARED MOORING SYSTEM ------ [used only for Mod_SharedMoor>0]
FAST.Farm 14 SharedMoorFile "" SharedMoorFile - Name of file containing shared mooring system input parameters (quoted string) [used only when Mod_SharedMooring > 0]
FAST.Farm 15 DT_Mooring 0.04 DT_Mooring - Time step for farm-level mooring coupling with each turbine (s) [used only when Mod_SharedMooring > 0]
AeroDyn driver 54* WrVTK_Type 1 WrVTK_Type - VTK visualization data type: (switch) {1=surfaces; 2=lines; 3=both}
Modified in OpenFAST v3.3.0
Module Line Flag Name Example Value
MoorDyn& 5 na Name Diam MassDen EA BA/-zeta EI Cd Ca CdAx CaAx
MoorDyn& 6 na (-) (m) (kg/m) (N) (N-s/-) (-) (-) (-) (-) (-)
MoorDyn& 7 na main 0.0766 113.35 7.536E8 -1.0 0 2.0 0.8 0.4 0.25
MoorDyn& 8* na ---------------------- POINTS --------------------------------
MoorDyn& 9* na ID Attachment X Y Z M V CdA CA
MoorDyn& 10* na (-) (-) (m) (m) (m) (kg) (m^3) (m^2) (-)
MoorDyn& 11* na 1 Fixed 418.8 725.383 -200.0 0 0 0 0
MoorDyn& 17* na ---------------------- LINES --------------------------------------
MoorDyn& 18* na ID LineType AttachA AttachB UnstrLen NumSegs Outputs
MoorDyn& 19* na (-) (-) (-) (-) (m) (-) (-)
MoorDyn& 20* na 1 main 1 4 835.35 20 -

&MoorDyn has undergone an extensive revision that leaves few lines unchanged. We recommend looking at a sample input file for the 5MW_OC4Semi_WSt_WavesWN regression test for reference rather than line by line changes in the above tables.

Removed in OpenFAST v3.3.0
Module Line Flag Name Example Value
MoorDyn& 5 NTypes 1 NTypes - number of LineTypes
MoorDyn& 10* NConnects 6 NConnects - number of connections including anchors and fairleads
MoorDyn& 20* NLines 3 NLines - number of line objects

*Exact line number depends on number of entries in various preceeding tables.

&MoorDyn has undergone an extensive revision that leaves few lines unchanged. We recommend looking at a sample input file for the 5MW_OC4Semi_WSt_WavesWN regression test for reference rather than line by line changes in the above tables.

OpenFAST v3.1.0 to OpenFAST v3.2.0

Added in OpenFAST v3.2.0
Module Line Flag Name Example Value
TurbSim 13 WrHAWCFF False WrHAWCFF - Output full-field time-series data in HAWC form? (Generates RootName-u.bin, RootName-v.bin, RootName-w.bin, RootName.hawc)
Removed in OpenFAST v3.2.0
Module Line Flag Name Example Value
TurbSim 14 Clockwise True Clockwise - Clockwise rotation looking downwind? (used only for full-field binary files - not necessary for AeroDyn)

OpenFAST v3.0.0 to OpenFAST v3.1.0

Added in OpenFAST v3.1.0
Module Line Flag Name Example Value
ServoDyn 60 AeroControlSec ---------------------- AERODYNAMIC FLOW CONTROL --------------------------------
ServoDyn 61 AfCmode 0 AfCmode - Airfoil control mode {0: none, 1: cosine wave cycle, 4: user-defined from Simulink/Labview, 5: user-defined from Bladed-style DLL} (switch)
ServoDyn 62 AfC_Mean 0 AfC_Mean - Mean level for cosine cycling or steady value (-) [used only with AfCmode==1]
ServoDyn 63 AfC_Amp 0 AfC_Amp - Amplitude for cosine cycling of flap signal (-) [used only with AfCmode==1]
ServoDyn 64 AfC_Phase 0 AfC_Phase - Phase relative to the blade azimuth (0 is vertical) for cosine cycling of flap signal (deg) [used only with AfCmode==1]
ServoDyn 74 CablesSection ---------------------- CABLE CONTROL -------------------------------------------
ServoDyn 75 CCmode 0 CCmode - Cable control mode {0: none, 4: user-defined from Simulink/Labview, 5: user-defined from Bladed-style DLL} (switch)
HydroDyn driver 6 WtrDens 1025 WtrDens - Water density (kg/m^3)
HydroDyn driver 7 WtrDpth 200 WtrDpth - Water depth (m)
HydroDyn driver 8 MSL2SWL 0 MSL2SWL - Offset between still-water level and mean sea level (m) [positive upward]
OpenFAST 21 MHK 0 MHK - MHK turbine type (switch) {0=Not an MHK turbine; 1=Fixed MHK turbine; 2=Floating MHK turbine}
OpenFAST 22 EnvCondSection ---------------------- ENVIRONMENTAL CONDITIONS --------------------------------
OpenFAST 23 Gravity 9.80665 Gravity - Gravitational acceleration (m/s^2)
OpenFAST 24 AirDens 1.225 AirDens - Air density (kg/m^3)
OpenFAST 25 WtrDens 1025 WtrDens - Water density (kg/m^3)
OpenFAST 26 KinVisc 1.464E-05 KinVisc - Kinematic viscosity of working fluid (m^2/s)
OpenFAST 27 SpdSound 335 SpdSound - Speed of sound in air (m/s)
OpenFAST 28 Patm 103500 Patm - Atmospheric pressure (Pa) [used only for an MHK turbine cavitation check]
OpenFAST 29 Pvap 1700 Pvap - Vapour pressure of working fluid (Pa) [used only for an MHK turbine cavitation check]
OpenFAST 30 WtrDpth 50 WtrDpth - Water depth (m)
OpenFAST 31 MSL2SWL 0 MSL2SWL - Offset between still-water level and mean sea level (m) [positive upward]
AeroDyn 15 39 UAStartRad 0.25 UAStartRad - Starting radius for dynamic stall (fraction of rotor radius) [used only when AFAeroMod=2; if line is missing UAStartRad=0]
AeroDyn 15 40 UAEndRad 0.95 UAEndRad - Ending radius for dynamic stall (fraction of rotor radius) [used only when AFAeroMod=2; if line is missing UAEndRad=1]
AeroDyn driver 34 Twr2Shft 3.09343 Twr2Shft - Vertical distance from the tower-top to the rotor shaft (m)
AirFoilTables 12* alphaUpper 5.0 alphaUpper ! Angle of attack at upper boundary of fully-attached region. (deg) [used only when UAMod=5] ! THIS IS AN OPTIONAL LINE; if omitted, it will be calculated from the polar data
AirFoilTables 13* alphaLower -3.0 alphaLower ! Angle of attack at lower boundary of fully-attached region. (deg) [used only when UAMod=5] ! THIS IS AN OPTIONAL LINE; if omitted, it will be calculated from the polar data
AirFoilTables 42* UACutout_delta "DEFAULT" UACutout_delta ! Delta angle of attack below UACutout where unsteady aerodynamics begin to turn off (blend with steady solution) (deg) [Specifying the string "Default" sets UACutout_delta to 5 degrees] ! THIS IS AN OPTIONAL LINE; if omitted, it will be set to its default value
FASTFarm 28 Mod_Wake 1 Mod_Wake - Switch between wake formulations {1:Polar, 2:Curl, 3:Cartesian} (-) (switch)
FASTFarm 62 Swirl False Swirl - Switch to include swirl velocities in wake [only used if Mod_Wake=2 or Mod_Wake=3] (-) (switch)
FASTFarm 63 k_VortexDecay
  1. k_VortexDecay - Vortex decay constant for curl (-)
FASTFarm 64 NumVortices DEFAULT NumVortices - The number of vortices in the curled wake model (-) [DEFAULT=100]
FASTFarm 65 sigma_D DEFAULT sigma_D - The width of the vortices in the curled wake model non-dimesionalized by rotor diameter (-) [DEFAULT=0.2]
FASTFarm 66 FilterInit DEFAULT FilterInit - Switch to filter the initial wake plane deficit and select the number of grid points for the filter {0: no filter, 1: filter of size 1} or DEFAULT [DEFAULT=1] [unused for Mod_Wake=1] (switch)
FASTFarm 67 k_vCurl 20 k_vCurl - Calibrated parameter for scaling the eddy viscosity in the curled-wake model (-) [only used if Mod_Wake=2 or Mod_Wake=3] [>=0] or DEFAULT [DEFAULT=2.0 ]
FASTFarm 68 Mod_Projection DEFAULT Mod_Projection - Switch to select how the wake plane velocity is project
FASTFarm 85 OutAllPlanes True OutAllPlanes - Output all wake planes at all time steps. [DEFAULT=False]

*non-comment line count, excluding lines contained if NumCoords is not 0, and including all OPTIONAL lines in the UA coefficients table.

Modified in OpenFAST v3.1.0
Module Line Flag Name Example Value
AeroDyn 16 AirDens "default" AirDens - Air density (kg/m^3)
AeroDyn 17 KinVisc "default" KinVisc - Kinematic viscosity of working fluid (m^2/s)
AeroDyn 18 SpdSound "default" SpdSound - Speed of sound in air (m/s)
AeroDyn 19 Patm "default" Patm - Atmospheric pressure (Pa) [used only when CavitCheck=True]
AeroDyn 20 Pvap "default" Pvap - Vapour pressure of working fluid (Pa) [used only when CavitCheck=True]
HydroDyn 5 WtrDens "default" WtrDens - Water density (kg/m^3)
HydroDyn 6 WtrDpth "default" WtrDpth - Water depth (meters)
HydroDyn 7 MSL2SWL "default" MSL2SWL - Offset between still-water level and mean sea level (meters) [positive upward; unused when WaveMod = 6; must be zero if PotMod=1 or 2]
Removed in OpenFAST v3.1.0
Module Line Flag Name Example Value
AeroDyn 21 FluidDepth 0.5 FluidDepth - Water depth above mid-hub height (m) [used only when CavitCheck=True]
ElastoDyn 7 EnvCondSection ---------------------- ENVIRONMENTAL CONDITION ---------------------------------
ElastoDyn 8 Gravity 9.80665 Gravity - Gravitational acceleration (m/s^2)
Added
Module Line Flag Name Example Value
SubDyn driver 21 [separator line] ---------------------- LOADS --------------------------------------------------------------------
SubDyn driver 22 nAppliedLoads 1 nAppliedLoads - Number of applied loads at given nodes false
SubDyn driver 23 ALTableHeader ALJointID Fx Fy Fz Mx My Mz UnsteadyFile
SubDyn driver 24 ALTableUnit (-) (N) (N) (N) (Nm) (Nm) (Nm) (-)
SubDyn driver 25 ALTableLine1 10 0.0 0.0 0.0 0.0 0.0 0.0 ""
  • SubDyn: the lines at n+1 and n+2 below were inserted after line n.
Added
Module Line Flag Name Example Value
SubDyn n OutCOSM Output cosine matrices with the selected output member forces (flag)
SubDyn n+1 OutCBModes Output Guyan and Craig-Bampton modes {0: No output, 1: JSON output}, (flag)
SubDyn n+2 OutFEMModes Output first 30 FEM modes {0: No output, 1: JSON output} (flag)

OpenFAST v2.6.0 to OpenFAST v3.0.0

ServoDyn Changes

  • The input file parser is updated to a keyword/value pair based input. Each entry must have a corresponding keyword with the same spelling as expected.
  • The TMD submodule of ServoDyn is replaced by an updated Structural Control module (StC) with updated capabilities and input file.
Removed in OpenFAST v3.0.0
Module Line Flag Name Example Value
ServoDyn 60 na ---------------------- TUNED MASS DAMPER ---------------------------------------
ServoDyn 61 CompNTMD False CompNTMD - Compute nacelle tuned mass damper {true/false} (flag)
ServoDyn 62 NTMDfile "NRELOffshrBsline5MW_ServoDyn_TMD.dat" NTMDfile - Name of the file for nacelle tuned mass damper (quoted string) [unused when CompNTMD is false]
ServoDyn 63 CompTTMD False CompTTMD - Compute tower tuned mass damper {true/false} (flag)
ServoDyn 64 TTMDfile "NRELOffshrBsline5MW_ServoDyn_TMD.dat" TTMDfile - Name of the file for tower tuned mass damper (quoted string) [unused when CompTTMD is false]
Added in OpenFAST v3.0.0
Module Line Flag Name Example Value
ServoDyn 60 na ---------------------- STRUCTURAL CONTROL --------------------------------------
ServoDyn 61 NumBStC 0 NumBStC - Number of blade structural controllers (integer)
ServoDyn 62 BStCfiles "unused" BStCfiles - Name of the files for blade structural controllers (quoted strings) [unused when NumBStC==0]
ServoDyn 63 NumNStC 0 NumNStC - Number of nacelle structural controllers (integer)
ServoDyn 64 NStCfiles "unused" NStCfiles - Name of the files for nacelle structural controllers (quoted strings) [unused when NumNStC==0]
ServoDyn 65 NumTStC 0 NumTStC - Number of tower structural controllers (integer)
ServoDyn 66 TStCfiles "unused" TStCfiles - Name of the files for tower structural controllers (quoted strings) [unused when NumTStC==0]
ServoDyn 67 NumSStC 0 NumSStC - Number of substructure structural controllers (integer)
ServoDyn 68 SStCfiles "unused" SStCfiles - Name of the files for substructure structural controllers (quoted strings) [unused when NumSStC==0]

OpenFAST v2.5.0 to OpenFAST v2.6.0

Many changes were applied to SubDyn input file format. You may consult the following example: :download:`(SubDyn's Input File) <./subdyn/examples/OC4_Jacket_SD_Input.dat>`: and the online SubDyn documentation.

Added in OpenFAST v2.6.0
Module Line Flag Name Example Value
AeroDyn 15   TwrTi 0.0000000E+00 6.0000000E+00 1.0000000E+00 1.0000000E-01 [additional column in Tower Influence and Aerodynamics table]
SubDyn 8 GuyanLoadCorr. False GuyanLoadCorection - Include extra moment from lever arm at interface and rotate FEM for floating
SubDyn 15 GuyanDampMod 0 GuyanDampMod - Guyan damping {0=none, 1=Rayleigh Damping, 2=user specified 6x6 matrix}
SubDyn 16 RayleighDamp 0.001, 0.003 RayleighDamp - Mass and stiffness proportional damping coefficients (Rayleigh Damping) [only if GuyanDampMod=1]
SubDyn 17 GuyanDampSize 6 GuyanDampSize - Guyan damping matrix size (square, 6x6) [only if GuyanDampMod=2]
SubDyn 18 GuyanDampMat 0.0000e+00 0.0000e+00 0.0000e+00 0.0000e+00 0.0000e+00 0.0000e+00
SubDyn -23 GuyanDampMat 0.0000e+00 0.0000e+00 0.0000e+00 0.0000e+00 0.0000e+00 0.0000e+00
SubDyn na CablesSection -------------------------- CABLE PROPERTIES -------------------------------------
SubDyn na CablesSection 0 NCablePropSets - Number of cable cable properties
SubDyn na CablesSection PropSetID EA MatDens T0
SubDyn na CablesSection (-) (N) (kg/m) (N)
SubDyn na RigidSection ---------------------- RIGID LINK PROPERTIES ------------------------------------
SubDyn na RigidSection 0 NRigidPropSets - Number of rigid link properties
SubDyn na RigidSection PropSetID MatDens
SubDyn na RigidSection (-) (kg/m)
HydroDyn 52 NBody 1 NBody - Number of WAMIT bodies to be used (-) [>=1; only used when PotMod=1. If NBodyMod=1, the WAMIT data contains a vector of size 6*NBody x 1 and matrices of size 6*NBody x 6*NBody; if NBodyMod>1, there are NBody sets of WAMIT data each with a vector of size 6 x 1 and matrices of size 6 x 6]
HydroDyn 53 NBodyMod 1 NBodyMod - Body coupling model {1: include coupling terms between each body and NBody in HydroDyn equals NBODY in WAMIT, 2: neglect coupling terms between each body and NBODY=1 with XBODY=0 in WAMIT, 3: Neglect coupling terms between each body and NBODY=1 with XBODY=/0 in WAMIT} (switch) [only used when PotMod=1]
ServoDyn 61 NumBStC 0 NumBStC - Number of blade structural controllers (integer)
ServoDyn 62 BStCfiles "unused" BStCfiles - Name of the files for blade structural controllers (quoted strings) [unused when NumBStC==0]
ServoDyn 63 NumNStC 0 NumNStC - Number of nacelle structural controllers (integer)
ServoDyn 64 NStCfiles "unused" NStCfiles - Name of the files for nacelle structural controllers (quoted strings) [unused when NumNStC==0]
ServoDyn 65 NumTStC 0 NumTStC - Number of tower structural controllers (integer)
ServoDyn 66 TStCfiles "unused" TStCfiles - Name of the files for tower structural controllers (quoted strings) [unused when NumTStC==0]
ServoDyn 67 NumSStC 0 NumSStC - Number of substructure structural controllers (integer)
ServoDyn 68 SStCfiles "unused" SStCfiles - Name of the files for substructure structural controllers (quoted strings) [unused when NumSStC==0]
AirFoilTables 12* alphaUpper 5.0 alphaUpper ! Angle of attack at upper boundary of fully-attached region. (deg) [used only when UAMod=5] ! THIS IS AN OPTIONAL LINE; if omitted, it will be calculated from the polar data
AirFoilTables 13* alphaLower -3.0 alphaLower ! Angle of attack at lower boundary of fully-attached region. (deg) [used only when UAMod=5] ! THIS IS AN OPTIONAL LINE; if omitted, it will be calculated from the polar data
AirFoilTables 42* UACutout_delta "DEFAULT" UACutout_delta ! Delta angle of attack below UACutout where unsteady aerodynamics begin to turn off (blend with steady solution) (deg) [Specifying the string "Default" sets UACutout_delta to 5 degrees] ! THIS IS AN OPTIONAL LINE; if omitted, it will be set to its default value

*non-comment line count, excluding lines contained if NumCoords is not 0, and including all OPTIONAL lines in the UA coefficients table.

Modified in OpenFAST v2.6.0
Module Line Flag Name Example Value
AeroDyn 15 9 TwrShadow 0 TwrShadow - Calculate tower influence on wind based on downstream tower shadow (switch) {0=none, 1=Powles model, 2=Eames model}
SubDyn 26 Joints JointID JointXss JointYss JointZss JointType JointDirX JointDirY JointDirZ JointStiff
SubDyn 27 Joints (-) (m) (m) (m) (-) (-) (-) (-) (Nm/rad)
SubDyn na Members MemberID MJointID1 MJointID2 MPropSetID1 MPropSetID2 MType COSMID
SubDyn na Members (-) (-) (-) (-) (-) (-) (-)
SubDyn na ConcentratedM CMJointID JMass JMXX JMYY JMZZ JMXY JMXZ JMYZ MCGX MCGY MCGZ
SubDyn na ConcentratedM (-) (kg) (kg*m^2) (kg*m^2) (kg*m^2) (kg*m^2) (kg*m^2) (kg*m^2) (m) (m) (m)
HydroDyn 48 ExtnMod 1 ExctnMod - Wave-excitation model {0: no wave-excitation calculation, 1: DFT, 2: state-space} (switch) [only used when PotMod=1; STATE-SPACE REQUIRES *.ssexctn INPUT FILE]
HydroDyn 49 RdtnMod 2 RdtnMod - Radiation memory-effect model {0: no memory-effect calculation, 1: convolution, 2: state-space} (switch) [only used when PotMod=1; STATE-SPACE REQUIRES *.ss INPUT FILE]
HydroDyn 50 RdtnTMax 60 RdtnTMax - Analysis time for wave radiation kernel calculations (sec) [only used when PotMod=1 and RdtnMod>0; determines RdtnDOmega=Pi/RdtnTMax in the cosine transform; MAKE SURE THIS IS LONG ENOUGH FOR THE RADIATION IMPULSE RESPONSE FUNCTIONS TO DECAY TO NEAR-ZERO FOR THE GIVEN PLATFORM!]
HydroDyn 51 RdtnDT 0.0125 RdtnDT - Time step for wave radiation kernel calculations (sec) [only used when PotMod=1 and ExctnMod>0 or RdtnMod>0; DT<=RdtnDT<=0.1 recommended; determines RdtnOmegaMax=Pi/RdtnDT in the cosine transform]
HydroDyn 54 PotFile "Barge" PotFile - Root name of potential-flow model data; WAMIT output files containing the linear, nondimensionalized, hydrostatic restoring matrix (.hst), frequency-dependent hydrodynamic added mass matrix and damping matrix (.1), and frequency- and direction-dependent wave excitation force vector per unit wave amplitude (.3) (quoted string) [1 to NBody if NBodyMod>1] [MAKE SURE THE FREQUENCIES INHERENT IN THESE WAMIT FILES SPAN THE PHYSICALLY-SIGNIFICANT RANGE OF FREQUENCIES FOR THE GIVEN PLATFORM; THEY MUST CONTAIN THE ZERO- AND INFINITE-FREQUENCY LIMITS!]
HydroDyn 55 WAMITULEN 1 WAMITULEN - Characteristic body length scale used to redimensionalize WAMIT output (meters) [1 to NBody if NBodyMod>1] [only used when PotMod=1]
HydroDyn 56 PtfmRefxt 0.0 PtfmRefxt - The xt offset of the body reference point(s) from (0,0,0) (meters) [1 to NBody] [only used when PotMod=1]
HydroDyn 57 PtfmRefyt 0.0 PtfmRefyt - The yt offset of the body reference point(s) from (0,0,0) (meters) [1 to NBody] [only used when PotMod=1]
HydroDyn 58 PtfmRefzt 0.0 PtfmRefzt - The zt offset of the body reference point(s) from (0,0,0) (meters) [1 to NBody] [only used when PotMod=1. If NBodyMod=2,PtfmRefzt=0.0]
HydroDyn 59 PtfmRefztRot 0.0 PtfmRefztRot - The rotation about zt of the body reference frame(s) from xt/yt (degrees) [1 to NBody] [only used when PotMod=1]
HydroDyn 60 PtfmVol0 6000 PtfmVol0 - Displaced volume of water when the body is in its undisplaced position (m^3) [1 to NBody] [only used when PotMod=1; USE THE SAME VALUE COMPUTED BY WAMIT AS OUTPUT IN THE .OUT FILE!]
HydroDyn 61 PtfmCOBxt 0.0 PtfmCOBxt - The xt offset of the center of buoyancy (COB) from (0,0) (meters) [1 to NBody] [only used when PotMod=1]
HydroDyn 62 PtfmCOByt 0.0 PtfmCOByt - The yt offset of the center of buoyancy (COB) from (0,0) (meters) [1 to NBody] [only used when PotMod=1]
HydroDyn 69-74 AddF0 0 AddF0 - Additional preload (N, N-m) [If NBodyMod=1, one size 6*NBody x 1 vector; if NBodyMod>1, NBody size 6 x 1 vectors]
HydroDyn 75-80 AddCLin 0 0 0 0 0 0 AddCLin - Additional linear stiffness (N/m, N/rad, N-m/m, N-m/rad) [If NBodyMod=1, one size 6*NBody x 6*NBody matrix; if NBodyMod>1, NBody size 6 x 6 matrices]
HydroDyn 81-86 AddBLin 0 0 0 0 0 0 AddBLin - Additional linear damping(N/(m/s), N/(rad/s), N-m/(m/s), N-m/(rad/s)) [If NBodyMod=1, one size 6*NBody x 6*NBody matrix; if NBodyMod>1, NBody size 6 x 6 matrices]
HydroDyn 87-92 AddBQuad 0 0 0 0 0 0 AddBQuad - Additional quadratic drag(N/(m/s)^2, N/(rad/s)^2, N-m(m/s)^2, N-m/(rad/s)^2) [If NBodyMod=1, one size 6*NBody x 6*NBody matrix; if NBodyMod>1, NBody size 6 x 6 matrices]
HydroDyn na Simple Coef Tab SimplCd SimplCdMG SimplCa SimplCaMG SimplCp SimplCpMG SimplAxCa SimplAxCaMG SimplAxCa SimplAxCaMG SimplAxCp SimplAxCpMG
HydroDyn na   (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-)
HydroDyn na Depth Coef Tab Dpth DpthCd DpthCdMG DpthCa DpthCaMG DpthCp DpthCpMG DpthAxCa DpthAxCaMG DpthAxCa DpthAxCaMG DpthAxCp DpthAxCpMG
HydroDyn na  
  1. (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-)
HydroDyn na Member Coef Tab MemberID MemberCd1 MemberCd2 MemberCdMG1 MemberCdMG2 MemberCa1 MemberCa2 MemberCaMG1 MemberCaMG2 MemberCp1 MemberCp2 MemberCpMG1 MemberCpMG2 MemberAxCd1 MemberAxCd2 MemberAxCdMG1 MemberAxCdMG2 MemberAxCa1 MemberAxCa2 MemberAxCaMG1 MemberAxCaMG2 MemberAxCp1 MemberAxCp2 MemberAxCpMG1 MemberAxCpMG2
HydroDyn na   (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-)
HydroDyn na OutList names see OutlistParameters.xlsx for new and revised output channel names
Removed in OpenFAST v2.6.0
Module Line Flag Name Example Value
HydroDyn 68 na ---------------------- FLOATING PLATFORM FORCE FLAGS -------------------------- [unused with WaveMod=6]
HydroDyn 69 PtfmSgF True PtfmSgF - Platform horizontal surge translation force (flag) or DEFAULT
HydroDyn 70 PtfmSwF True PtfmSwF - Platform horizontal sway translation force (flag) or DEFAULT
HydroDyn 71 PtfmHvF True PtfmHvF - Platform vertical heave translation force (flag) or DEFAULT
HydroDyn 72 PtfmRF True PtfmRF - Platform roll tilt rotation force (flag) or DEFAULT
HydroDyn 73 PtfmPF True PtfmPF - Platform pitch tilt rotation force (flag) or DEFAULT
HydroDyn 74 PtfmYF True PtfmYF - Platform yaw rotation force (flag) or DEFAULT

OpenFAST v2.4.0 to OpenFAST v2.5.0

  • InflowWind
    • The input file parser is updated to a keyword/value pair based input. Each entry must have a corresponding keyword with the same spelling as expected. See :numref:`input_file_overview` for an overview.
    • Driver code includes ability to convert between wind types
Added in OpenFAST v2.5.0
Module Line Flag Name Example Value
IfW driver 6 [separator line] ===================== File Conversion Options =================================
IfW driver 7 WrHAWC false WrHAWC - Convert all data to HAWC2 format? (flag)
IfW driver 8 WrBladed false WrBladed - Convert all data to Bladed format? (flag)
IfW driver 9 WrVTK false WrVTK - Convert all data to VTK format? (flag)
InflowWind 7 VFlowAng 0 VFlowAng - Upflow angle (degrees) (not used for native Bladed format WindType=7)
Modified in OpenFAST v2.5.0
Module Line Flag Name / section Example Value
MoorDyn na added CtrlChan column in LINE PROPERTIES table  
Renamed in OpenFAST v2.5.0
Module Line Previous Name New Name Example Value
InflowWind 17 Filename FileName_Uni "Shr11_30.wnd" FileName_Uni - Filename of time series data for uniform wind field. (-)
InflowWind 18 RefHt RefHt_Uni 90 RefHt_Uni - Reference height for horizontal wind speed (m)
InflowWind 21 Filename FileName_BTS "unused" FileName_BTS - Name of the Full field wind file to use (.bts) (-)
InflowWind 23 Filename FileNameRoot "unused" FileNameRoot - WindType=4: Rootname of the full-field wind file to use (.wnd, .sum); WindType=7: name of the intermediate file with wind scaling values
InflowWind 35 RefHt RefHt_Hawc 90 RefHt_Hawc - reference height; the height (in meters) of the vertical center of the grid (m)
InflowWind 47 PLExp PLExp_Hawc 0.2 PLExp_Hawc - Power law exponent (-) (used for PL wind profile type only)
InflowWind 49 InitPosition(x) XOffset 0 XOffset - Initial offset in +x direction (shift of wind box)

OpenFAST v2.3.0 to OpenFAST v2.4.0

Additional nodal output channels added for :ref:`AeroDyn<AD-Nodal-Outputs>`, :ref:`BeamDyn<BD-Nodal-Outputs>`, and :ref:`ElastoDyn<ED-Nodal-Outputs>`.

Added in OpenFAST v2.4.0
Module Line Flag Name Example Value
HydroDyn 53 ExctnMod 0 ExctnMod - Wave Excitation model {0: None, 1: DFT, 2: state-space} (-)
OpenFAST 44 CalcSteady true CalcSteady - Calculate a steady-state periodic operating point before linearization? [unused if Linearize=False] (flag)
OpenFAST 45 TrimCase 3 TrimCase - Controller parameter to be trimmed {1:yaw; 2:torque; 3:pitch} [used only if CalcSteady=True] (-)
OpenFAST 46 TrimTol 0.0001 TrimTol - Tolerance for the rotational speed convergence [used only if CalcSteady=True] (-)
OpenFAST 47 TrimGain 0.001 TrimGain - Proportional gain for the rotational speed error (>0) [used only if CalcSteady=True] (rad/(rad/s) for yaw or pitch; Nm/(rad/s) for torque)
OpenFAST 48 Twr_Kdmp 0 Twr_Kdmp - Damping factor for the tower [used only if CalcSteady=True] (N/(m/s))
OpenFAST 49 Bld_Kdmp 0 Bld_Kdmp - Damping factor for the blades [used only if CalcSteady=True] (N/(m/s))
InflowWind 48 InitPosition(x) 0.0 InitPosition(x) - Initial offset in +x direction (shift of wind box) [Only used with WindType = 5] (m)
AeroDyn 13 CompAA False CompAA - Flag to compute AeroAcoustics calculation [only used when WakeMod=1 or 2]
AeroDyn 14 AA_InputFile "unused" AA_InputFile - Aeroacoustics input file
AeroDyn 35 [separator line] ====== OLAF cOnvecting LAgrangian Filaments (Free Vortex Wake) Theory Options ================== [used only when WakeMod=3]
AeroDyn 36 OLAFInputFileName "Elliptic_OLAF.dat" OLAFInputFileName - Input file for OLAF [used only when WakeMod=3]
AirFoilTables 4* BL_file "unused" BL_file - The file name including the boundary layer characteristics of the profile. Ignored if the aeroacoustic module is not called.
Modified in OpenFAST v2.4.0
Module Line New Flag Name Example Value Previous Flag Name/Value
AirFoilTables 40* filtCutOff "DEFAULT" filtCutOff - Reduced frequency cut-off for low-pass filtering the AoA input to UA, as well as the 1st and 2nd deriv (-) [default = 0.5] [default = 20]

*non-comment line count, excluding lines contained if NumCoords is not 0.

OpenFAST v2.2.0 to OpenFAST v2.3.0

Removed in OpenFAST v2.3.0
Module Line Flag Name Example Value
AeroDyn Airfoil Input File - Airfoil Tables 2 Ctrl 0 Ctrl ! Control setting (must be 0 for current AirfoilInfo)
Added in OpenFAST v2.3.0
Module Line Flag Name Example Value
AeroDyn Airfoil Input File - Airfoil Tables 2 UserProp 0 UserProp ! User property (control) setting
AeroDyn 37 AFTabMod 1 AFTabMod - Interpolation method for multiple airfoil tables {1=1D interpolation on AoA (first table only); 2=2D interpolation on AoA and Re; 3=2D interpolation on AoA and UserProp} (-)

OpenFAST v2.1.0 to OpenFAST v2.2.0

No changes required.

OpenFAST v2.0.0 to OpenFAST v2.1.0

Added in OpenFAST v2.1.0
Module Line Flag Name Example Value
BeamDyn driver 21 GlbRotBladeT0 True GlbRotBladeT0 - Reference orientation for BeamDyn calculations is aligned with initial blade root?

OpenFAST v1.0.0 to OpenFAST v2.0.0

Removed in OpenFAST v2.0.0
Module Line Flag Name Example Value
BeamDyn 5 analysis_type analysis_type - 1: Static analysis; 2: Dynamic analysis
Added in OpenFAST v2.0.0
Module Line Flag Name Example Value
AeroDyn 22 SkewModFactor "default" SkewModFactor - Constant used in Pitt/Peters skewed wake model {or "default" is 15/32*pi} (-) [used only when SkewMod=2; unused when WakeMod=0]
AeroDyn 30 Section header ====== Dynamic Blade-Element/Momentum Theory Options ============================================== [used only when WakeMod=2]
AeroDyn 31 DBEMT_Mod 2 DBEMT_Mod - Type of dynamic BEMT (DBEMT) model {1=constant tau1, 2=time-dependent tau1} (-) [used only when WakeMod=2]
AeroDyn 32 tau1_const 4 tau1_const - Time constant for DBEMT (s) [used only when WakeMod=2 and DBEMT_Mod=1]
BeamDyn 5 QuasiStaticInit True QuasiStaticInit - Use quasi-static pre-conditioning with centripetal accelerations in initialization (flag) [dynamic solve only]
BeamDyn 11 load_retries DEFAULT load_retries - Number of factored load retries before quitting the simulation
BeamDyn 14 tngt_stf_fd DEFAULT tngt_stf_fd - Flag to use finite differenced tangent stiffness matrix (-)
BeamDyn 15 tngt_stf_comp DEFAULT tngt_stf_comp - Flag to compare analytical finite differenced tangent stiffness matrix (-)
BeamDyn 16 tngt_stf_pert DEFAULT tngt_stf_pert - perturbation size for finite differencing (-)
BeamDyn 17 tngt_stf_difftol DEFAULT tngt_stf_difftol - Maximum allowable relative difference between analytical and fd tangent stiffness (-)
BeamDyn 18 RotStates True RotStates - Orient states in the rotating frame during linearization? (flag) [used only when linearizing]

FAST v8.16 to OpenFAST v1.0.0

The transition from FAST v8 to OpenFAST is described in detail at :ref:`fast_to_openfast`.

Removed in OpenFAST v1.0.0
Module Line Flag Name Example Value
OpenFAST 18 CompSub 0 CompSub - Compute sub-structural dynamics (switch) {0=None; 1=SubDyn}
Added in OpenFAST v1.0.0
Module Line Flag Name Example Value
OpenFAST 18 CompSub 0 CompSub - Compute sub-structural dynamics (switch) {0=None; 1=SubDyn; 2=External Platform MCKF}
AeroDyn 12 CavityCheck False CavitCheck - Perform cavitation check? (flag)
AeroDyn 17 Patm 9999.9 Patm - Atmospheric pressure (Pa) [used only when CavitCheck=True]
AeroDyn 18 Pvap 9999.9 Pvap - Vapor pressure of fluid (Pa) [used only when CavitCheck=True]
AeroDyn 19 FluidDepth 9999.9 FluidDepth - Water depth above mid-hub height (m) [used only when CavitCheck=True]